Micrometer weighing instrument



Sept. 14 1926.

C. W. CALDWELL IIICROIBTER WEIGHING INSTRUMENT Filed July 15,

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Patented Sept. 14, 1926.

UNITED STATES CHARLES WILLIAM CALDWELL, OF BEREA, JOHANNESBURG,

TRANSVAAL, SOUTH AFRICA.

MICROMETER, WEIGHING INSTRUMENT.

Application filed my 15, 1925. Serial No. 43,672.

The present [invention has reference to weighing instruments of the kindin whlch a pivoted beam is provided with a poise movable along the beamby means of a socalled micrometer screw actuated by hand.

The purpose of the invention is to provide an inexpensive arrangementfor exhibiting the weight of the goods in such a manner that the figuresare easily read by w the purchaser.

The invention is illustrated in the accompanying drawing in which' Fig'.I is a View of the instrument as seen by the urchaser.

Fig. I is a plan.

Fig. III is a partial end view as seen from the direction of the arrowA, Fig. II. but showing parts diflerently positioned from Figs. I andII.

Fig. IV is an enlarged sectional view taken on IVIV Fig. III.

Fig. V is similar to Fig. IV, but shows the parts differentlypositioned.

2 indicates a base on which is a standard 3 carrying the beam 4 by meansof pivots 5.

The scale pan 6 and the goods thereon, on one side of the pivots. arecounterbalanced by the poise 7 on the other side of the pivots. Thepoise is shifted along the beam by means of the micrometer screw 8'rotatably mounted in the beam and actuated by the hand wheels 9.

The rim of the poise 7 moves in close proximity to the edge 10 of aplate 11- fixed to the beam. On said plate is a numbered scale 12 withwhich a line13 on the rim co-operates to indicate pounds; and on the rimof the poise is a further numbered scale 14 with which the edge 10 ofthe plate 11 4 co-operates to indicate ounces.

The scales .12 and 14 are arranged to be read from the salesmans side ofthe instrument; but are not easily visible to a purchaser standing atthe opposite side of the 45 instrument from the salesman.

For exhibiting the weight to the customer the invention provides theadditional ounce and pound indications 15, 16.

The ounce scale 15 is marked on the rim 50 of a light drum 17 andco-operates with the edge 18 of a plate 19 fixed to the beam. Said scale15 is similar to the scale 14' ex cept that its. numerals are arrangedoppositely to those on the rim of the poise so as to be upright whenviewed from the customers side of the instrument.

The drum 17 is arranged to rotate with the poise 7, but not to traverse.In the instrument shown the shaft 20 in which the micrometer screw 8 isformed, is arranged both to rotate and to traverse. Consequently thedrum is not in this case fixed to said shaft but is rotatably mounted bymeans of its hollow journal 21 in the bearing 22 at the end of the beam.said bearing having a detachable cap 23. Rotational engagement of theshaft and the drum is effected by a spline 24.

The weight in pounds is preferably indicated by numerals 16 marked on adial 25 arranged to face the customer and rotatably mounted on anextension 26 of the beam. Said numerals are preferably ex hibited one ata time through an aperture 27 in the plate 19, the dial being for thatpurpose arranged behind said plate.

I11 order to give a perfectly clear and definite pound indication, it ispreferred to arrange the dial 25 toremain stationary during the greaterpart of each revolution of the assembly comprising the poise 7. shaft 20and drum 17. The dial is rotated step-by-step, the rotation taking placeat about the moment when the nought ounce figure is at the indicatingedge 18. and the 5 of the drum for the greater part of itscircumferential extent, and the angularly disposed portion 29 of whichis of correspondingly limited angular extent.

Movement of said portion 29* past the crown wheel rotates the latterthrough one tooth space, which-is equal to the angu ar spacing of thepound numerals 16. Fig.

IV shows the thread portion 29" just on the point of moving the crownwheel to exhibit a higher pound. figure. and Fig. V shows the movementjust completed.

Whilst only the inclined portion. 29 of the thread is required to rotatethe crown wheel, it is preferred to provide the complete circumferentialthread, since the noir inclined portion ot the same serves to hold thedial stationary, and the crown wheel is at all times positively engagedby the drum. To insure such positive engagement, the thread is continuedas indicated at 29" for a short distance past the inc ined portion 29"and parallel with the commencing end 29.

In order to minimize the shock of thus suddenly rotating the dial 25,the spring 30 may be provided. This spring is secured to the drum 1? atone end and its other end 31 is positioned to make engagen'ient with theteeth of the crown wheel. Sair end is rather longer circunrtcrentiallythan the inclined thread portion 29, so that whatever the direction '1rotation of the drun'i said endengages its tooth sli 'htlv b the portionit) en ages a too Llaid end also is so inclined that wnen it yieldinglyengagement with t. the crown wheel tor 1-; coming movement andeliminating impact due to loose contact between the thread and the crownwheel.

I claim 1. In a nicrometer wei hing the combination of a pivoted beam,traversible along the same, a rotatabl for traversing the poise, a drum1' with the shaft a id having a scale on "dapted to be instrument,

a p a e s ratt c t atable its 'im properly viewed trom the customer'sside of the instrument, a fixed part with which said scale registers, arotatable member, and means operativel con necting said rotatable membervith said shaft to cause said member to rotate with less angulardisplacement than the shaft, said member indicating at the customersside of the instrument values of a higher denomination than the scale.

2. In a micrometer wei the combination of a pivoted traversable alongthe same, a rota for travcrs' 1g the poise, d .r rotatable with theshaft and having a Stt Jim ad: pted to be properly viewed from thecustomers side of the instrument, a fixed part with which said scaleregisters, a rotatable member, means placing said rotatable memher indriving engagement with the shaft and causing said member to rotateintermittently when the shaft rotates continuously, said memberindicating at the customer's side of the instrument values of a higherdenomination than the scale.

3. In a micrometer weighing instrument, the combination of a pivotedbeam. a poise traversable along the same, rotatable shaft for traversingthe poise, a drum rotatable with the shaft, and having a scale on itsrim adapted to be properly viewed from the customers side of theinstrument, a lined part with which said scale registers, a rotatablenumbered dial facing the customers side of the instrument, meansrotating said dial intermittently when the shaft rotates continuously,and aperturcd means covering said dial to exhibit its numbersindividually.

t. In a micrometer weighing instrm'nent, the combination oil? a pivotedbeam, a poise traversable along the same, a rotatable shaft fortraversing the poise, a drum rotatable with the shaft and having a scaleon its rim adapted to be properly viewed from the customers side ot theinstrument, a fixed part with which said scale registers, and arotatable member driven from said drum so to have a less angulardisplacement than the drum, said member indicating at the customers sideor the instrument values of a higher denon'iination than the scale.

5. In a micrometer weighing instrument, the coi'nbination of a pivotedbeam, :1 poise traversable along the beam, a rotatable shaft fortraversing the poise, a drum rotatable with the shaft and having a scaleon its rim adapted to be properly viewed from the customers side of theinstrument, a fixed part with which sait scale registers, a rotat ablemember tacing the customers side of the instrument and indicatingweights of: a higher denomination, a crown wheel fixed to said rotatablemember and a thread on a part rotating with the shatt and engaging saidcrown wheel to rotate the same.

In a micrometer weighing instrument, the combination 01 a pivoted beam,a poise traversable along the beam, a rotatable shaft for traversing thepoise, a drum rotatable with the shaft and having a scale on its rimadapted to be properly viewed from the customers side of the instrument,a lixed part with which said scale i'eg ;e1's, a rotatable member facingthe ci'istoiners side of the instrument and indicating weights of ahigher denomination than the scale, a crown wheel fixed to saidrotatable member, and a part rotating with the shaft having a drunkenthread engaging said crown wheel to rotate the same step by step.

7. In a weighing instriunent, a rotatable member formed with a drunkenscrew thread C()H1P1'lllli. a uniplanar portion of con iderablecircuinferential extent and an inclined portion, a rotatable crown wheelin 01 ment with said screw thre: d for intcrnidtcut rotation, and springmean rotating with t ie rotatable member and shaped to engage the crow;wheel in advance of the inclined poi" tion of the thread and itself soinclined as yieldingly to hold the crown wheel into engagement with theface of the thread.

In testimony whereof I have atlixed my signature.

